What if you owe taxes from last year….?

OK so here is the deal! Last year my exhusband and I filed our taxes together bc we were still married. When we filed we thought we had all the w-2s and had forgot that he worked for a company for 2 weeks in 2010. So we had to file an ammendment, we had already received our refund so we owed I think $ 500. We got a divorce shortly after and I was told he had paid that off. I received a letter this year saying we now owed $ 1600 bc of intrest. I filed my taxes and since I focused on school and didnt work all that much Im only getting back $ 1800- I did my taxes with H&R Block and and am told that my refund is supposed to be here in 3 days. I have not received any notice from the IRS or from H&R Block saying that money will be coming out of my refund and when I check the “Wheres my refund” page it says my refund is scheduled to be here on time- does that mean they will not be taking from my refund? Also if they do take from my refund will they take all of it or do half out of mine half out of his? He has not filed for this year yet.